Pump for pumping molten metal



Feb. 20, 1934. e. H. WHITE PUMP FOR PUMPING MOLTEN METAL Fil ed July 7,1950 I 72116722507" ffirZera Wife 5 Patented Feb. 20, 1934 UNITED STATESPUMP FOB. romme MOL'IEN mz'rar.

George Herbert White, Philadelphia, Pa., aesig'nor to Patent ProductCorporation of Ohicago, a corporation of Delaware Application July '1,1530. Serial No. 465,912

1 Claim. (or 22-10) My invention relates to improvements in pumps forpumping molten metal and the like and has for one object to provide anew and improved form of pump which will be self cleaning. Other objectsof my invention .will appear throughout the specification and claim.

My invention is illustrated more or less diagrammatically in theaccompanying drawing, wherein- Figure 1 is a side elevation in partsection of a pump and plunger;

Figure 2 is a side elevation of a modified form of plunger;

Figure 3 is a side elevation in part section of a modified form ofcylinder and plunger;

Figures 4, 5 and 6 are similar views showing further modified forms.

Like parts are indicated by like characters throughout the specificationand drawing.

When molten metal such as lead is cast by means of a pump such as usedin connection with type setting machinery, die casting and the like,experience shows that there is a tendency for the pump piston andcylinder to clog or become foul from the presence of refuse such asmetallic oxides and the like and periodically therefore it is necessaryto withdraw the plunger from the cylinder to enable the plunger andcylinder to be cleaned.

This difiiculty has to some extent been obvi-- ated in the past byproviding a plurality of annular grooves in the piston or plunger. Theseannular grooves traveling along the cylinder with their sharp edgesadjacent the cylinder wall tend to scrape oil the deposit and increasethe length of time during which operation can take place withoutcleaning but as soon as the annular grooves are filled with refuse theplunger must be withdrawn and the grooves cleaned out.

I have discovered that if the plunger or the cylinder 5 or both areprovided with one or more spiral grooves extending throughout such partof the cylinder asv will permit the groove to be exposed to both endswhen pressure is applied, that some of the molten metal will leak backthrough such grooves and carry with it the deposit which would otherwiseremain in the grooves and ultimately clog the pump. The leakage throughthese grooves is small enough so that it does not adversely aflect theoperation of the device but is sufiicient to provide a wiping stream orflow through the spiral groove whereby the material is washed out.

In Figure l, A is a melting pot. It contains a mass of molten metal AThe lug A and pin A indicate any suitable support for the pot. Immersedin the body of molten metal in the pot is a pump cylinder A having adiso0 charge spout or passage A terminating in a discharge nozzle Awhich is' adapted to be brought'into register with the mold by a ysuitable means forming no part of my invention and not here shown. A isa port leading through the wall of the cylinder and communicating withthe body of molten metal so that when the piston is withdrawn, the portis opened, molten metal flows in to fill the cylinder. When the pistonmoves forward the port is closed first and thereafter pressure isapplied by the piston or, plunger to the metal in the cylinder to causeit to be forced out through the pipe A and nozzle A.

B is a rock arm adapted to be operated by 7 any means not shown to causepiston movement. This rock arm is pivoted to a piston rod B which pistonrod in turn is pivoted to the piston B. B is a handle of 'wood or othersuitable insulating material on the piston rod whereby so the piston rodand piston may be manipulated by hand when desired to withdraw them fromworking relation with the pump. In Figure 1, the inner wall of thecylinder is shown as being smooth. The outer periphery of the piston has35 a single spiral groove B wound threadwise about the piston so as toprovide sharp scraping edges in opposition to the cylinder wall and soas to provide an elongated spiral escape passage from the interior ofthe cylinder about the periphery of the piston and between it and thecylinder communicating at its other end with the body of material in thepot.

In Figure 2, there are two spiral passages B B as a substitute for thesingle spiral passage B of Figure 1. In Figure 3 the spiral passage i3is located in the single peripheral wall of the'cylinder and in thiscase the piston is shown provided with a plurality of annular grooves 13In Figure 4 the piston has the single 10o spiral groove 3 but thecylinder has an additional spiral groove B of the same pitch as thegroove 3* and traveling in the same direction. In Figure 5, the spiralgroove B on the piston is associated with a spiral groove B in the wall05 of the cylinder but in this case the two grooves are wound inopposite directions. In Figure 6 there is associated with the groove Bon the piston a groove l3 in the cylinder wound in the same directionbut, of different pitch. lio

Many other combinations of grooving might be provided depending uponcircumstances but they all have this in common, that there is provided asharp shouldered cleaning or refuse receiving groove and that groovewhether in. the cylinder or in the piston or in both is wound screwthreadwise so as to provide a long spiral passage through which moltenmetal may flow when pressure is applied to the piston so that suchmolten metal at each piston stroke may tend to clean out and dischargefrom the piston and cylinder the fouling material or refuse which by thepiston reciprocation is caused to be scraped off from the opposed pistonand cylinder surfaces and deposited in the groove CERTIIFHCATE v PatentNo. l,94i7,8l8.

mergers I claim:

In combination, a melting pot, a cylinder projecting upwardly from thebottom of the pot and adapted to be entirely immersed in the moltenmetal, a cylindrical opening at the top, an intake'port through thewallof the cylinder adjacent the bottom of the pot, a piston adapted toreciprocate in the cylinder, a tortuous passage bounded by the cylinderand the piston communicating with the space beneath the piston withinthe cylinder at one end and with the body of metal above the cylinder atthe other end, the edges of the walls bounding the tortuous passagebeing sharp.

G. HERBERT WHITE.

or connection.

February 20, 1934.

GEQRGE HERBERT WHII'IIE.

it is hereby certified that the above numbered patent was erroneouslyissued to "Patent Product Corporationoi Chicago, a corporation ofDelaware," whereas said Letters Patent should have been issued toChester A.

Macomic, Chicago lllinois, said Macomic being assignee by mesne assign-,lnents oi the entire interest in said invention, as shown by therecords of assignments in this office; and that the said Letters Patentshould be read with this correction therein that the same may conform tothe record of the case in the Patent Otiice.

Signed and sealed this 3rd day oi April, A. n. 1934.-

(Seal) 1F. Vi. Hopkins Acting Commissioner of Patents.

